For years, companies have marketed products for either hair growth or hair growth retardation, with limited success. From mechanical procedures to compositions containing biologically active ingredients, numerous means are available for the consumer. Use of hair dyes to color hair, require frequent repetitions and are not often effective in hiding the appearance of hair on the skin.
Especially in suppressing hair growth, the prior art has taught the use of numerous actives including biological enzymes, plant extracts and enzyme inhibitors. For example, U.S. Pat. No. 6,375,948 teaches the use of an extract of a plant of the family Juniperus or a malt, an elastase inhibitor or neutral endopeptidase inhibitor and a proteolytic enzyme to suppress hair growth. In U.S. Pat. No. 6,407,056, the patent teaches a method of delaying mammalian hair growth comprising topically applying an effective amount of a composition comprising a serine protease and a pharmaceutically or cosmetically acceptable vehicle.
The references discussed above have limited and only short term usefulness. Other references turn to the factors that are believed to contribute to hair growth to develop formulas for regulating hair growth.
For example, angiogenesis is the fundamental process by which new blood vessels are formed. The process involves the migration of vascular endothelial cells into tissue, followed by the condensation of such endothelial cells into vessels. Angiogenesis involves a complex interplay of molecules that stimulate and molecules that inhibit the growth and migration of endothelial cells. In U.S. Pat. No. 6,391,850, it was found that an anti-angiogenic, SLED, stimulated the growth of hair. It was believed that SLED affected hair growth by mediating angiogenesis within the hair follicle.
Sphingo Glycolipids, such as phytosphingosine (known to be an anti-angiogenic), have been used in skin care compositions to aid in hair growth. For example, U.S. Pat. No. 5,565,207 (“Patent '207”) teaches the use of a scalp moisturizer comprising a steroid glycoside and/or a triterpenoid glycoside, a sphingo glycolipid and a follicular hormone and/or an adrenocortical hormone. Patent '207 recognizes the use of the scalp moisturizer to stimulate hair growth.
It is important to note that the references discussed above teach the use of anti-angiogenics to aid in promoting hair growth.
Yet another factor believed to contribute to hair growth is Ornithine Decarboxylase (OCD), an enzyme that catalyzes the decarboxylation of ornithine to putrescine. The reaction is the first step in the biosynthesis of the polyamides known as spermidine and spermine. The polyamides are known to play an important role in cell growth and proliferation. U.S. Pat. No. 4,720,489 (“Patent '489”) teaches the use of ornithine decarboxylase inhibitors to retard hair growth. Patent '489 specifically teaches against the use of certain ornithine decarboxylase inhibitors that can have secondary pharmacological effects.
In summary, the references discussed above teach that anti-angiogenic agents promote hair growth while certain ornithine decarboxylase inhibitors retard hair growth. Still other references teach compositions with only limited efficacy.
There still remains a need for a novel composition and method for inhibiting hair growth that has prolonged efficacy that can be accomplished preferably by manipulating the numerous factors that contribute to hair growth.